Ask the Doctor: Cramping Issues During Longer Races

Could eating pasta before my race be a factor?

Question: I often get cramps during a race (generally not a 21km, but almost always on a 42km). I have been taking potassium and sodium, but it does not seem to help much.

What I find most interesting is that I seem to start cramping a day or two before the race. I do have a little extra pasta for two or three days before a big race and I am starting to think that this may be linked to my problem. My cramps before are often in my feet and during a race they can be in either leg in many muscle groups. I will try my next race with no pasta before. Could this be the problem?

Answer: Cramping during long races is difficult problem for many runners. For a long time, electrolyte imbalances and dehydration have been blamed for this problem. The current consensus is that cramping during exercise is due to premature muscle fatigue; the nervous system is unable to relax the muscle once it has contracted.

Cramping at rest is a different phenomenon; electrolyte and fluid imbalances probably play more of a role in cramping at rest. Some people are susceptible to cramping, possibly due to a metabolic or muscle disorder. Cramping is a problem that sometimes runs in families (genetic).

It is interesting that increasing your intake of pasta seems to cause cramping. This may be due to gluten intolerance. Another possible cause is a fluid imbalance due to the storage of additional glycogen (3-4 grams of water are stored for each gram of glycogen stored). Since it seems that the extra pasta is a common factor with these episodes of cramping, try eating gluten free carbohydrates prior to long training runs to see if cramping occurs. You may also just maintain your usual diet and add carbohydrates during your run.

Since you do not have cramping during half marathons, it is possible that increasing your long training runs will decrease the risk of muscle fatigue and possibly decrease cramping during marathons.

Try these steps, but if the problem persists, evaluation by a physician may help determine if there is a metabolic, endocrine, nervous system or muscular cause of your problem. You could also be tested for Celiac disease.